What is the expected behavior after introducing use just 2FA for login ?

[Mishco]

We are introducing oidc 2FA (only as a single option instead of multiple options for login). What should be the expected behavior? Is it possible that the user may get an error such as:

{ "error" : "Internal server error: "Unauthorized (CSRF)" " } 

When using the normal login option (not 2fa)?
With 2FA there is no issue, login works well.